18148993 has 4 divisors (see below), whose sum is σ = 18328788. Its totient is φ = 17969200.

The previous prime is 18148973. The next prime is 18149017. The reversal of 18148993 is 39984181.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11242609 + 6906384 = 3353^2 + 2628^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18148993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18148973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 89746 + ... + 89947.

It is an arithmetic number, because the mean of its divisors is an integer number (4582197).

Almost surely, 2^18148993 is an apocalyptic number.

It is an amenable number.

18148993 is a deficient number, since it is larger than the sum of its proper divisors (179795).

18148993 is a wasteful number, since it uses less digits than its factorization.

18148993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179794.

The product of its digits is 62208, while the sum is 43.

The square root of 18148993 is about 4260.1634945152. The cubic root of 18148993 is about 262.7952499514.

The spelling of 18148993 in words is "eighteen million, one hundred forty-eight thousand, nine hundred ninety-three".